Borchardt said the inspections revealed that "some equipment, mainly pumps, were not operable when tested or lacked acceptance criteria. Some equipment was actually missing from the locations or dedicated to other activities, and in some cases, plant modifications had rendered the strategies that were developed at the time unworkable." But, he added, "we didn't find any cases where ultimately the [safety] function could not be performed."
Miller said the Fukushima disaster has focused the task force on the impacts of multiple threats to nuclear plants, such as a major fire and an earthquake, or an earthquake and flooding, that could knock out power for a plant's emergency equipment. Backup battery power for crucial safety equipment is only adequate for four to eight hours of emergency use at U.S. plants, Miller noted. The Fukushima accident forces a re-evaluation of whether that is enough protection, he concluded.
The current NRC regulations, called the station blackout rule, do not consider the impact of disasters that could cut off both on-site and off-site power simultaneously, Miller said.
New look at generators and vents
"As a result, the regulatory guidance assumed that the event causing the off-site power disturbance does not impact on-site power sources," he said. "And therefore the availability of on-site power is based on historic reliability of emergency diesel generators to start and perform their safety function when called upon."
The four- and eight-hour battery backup capabilities assume that outside power can be promptly restored. "In the case of an extreme external event, it might take days to restore [outside] AC power, as was the case at Fukushima," Miller said.
Miller also raised the issue of the vents that lead out of the wetwell, or torus, at the bottom of the Mark I reactors at Fukushima. When reactor fuel assemblies melted during the accident, hydrogen gas built up at high pressures inside the torus. Instead of exiting the reactor containment structure, hydrogen is presumed to have leaked from the venting system and exploded.
After the Three Mile Island accident, U.S. Mark I owners were required to install hardened exhaust vents, Miller noted. But the regulation did not specify a design for the vent configurations, nor did the regulations require a specific inspection program for the vents, he said. The designs in the United States vary, he added, and there are differences in the number and location of valves that might have to be operated in an emergency situation.
The venting systems "were not specifically designed for operation during a long-term station blackout," he added. "Therefore, depending on a plant-specific design, it may be a challenge to open the vent path in a scenario like the Fukushima accident."
He summed up, "in evaluating potential new [safety] requirements, the [NRC] staff tends to lean more toward the quantitative cost-benefit aspects of the regulatory analysis rather than the qualitative defense-in-depth consideration. This can result in more weight to protection strategies and less balanced approach to defense in depth."
An NRC requirement that plant owners make major modifications to reflect new safety standards is called the "back-fit" rule, and it includes a balancing of safety benefits and regulatory costs.
Commissioner Kristine Svinicki said Miller's discussion suggested that "you could quickly find yourself swimming in the waters of back-fit. ... That is something the task force is having to confront."
"We are confronting it," Miller said. "It is an awkward time."
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
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21 Comments
Add CommentMiller said. "It is an awkward time." ...really! How is this time any awkward than any other time when they don't want to do something?
Reply | Report Abuse | Link to thisS.A., did you fire your editors? When you do not edit your articles, it makes it difficult to read.
Fukushima planned for a 100-year, 15 foot tsunami and they got a 1000-year, 45 foot one.
Reply | Report Abuse | Link to thisThese Dark Swan events can be planned for, but at what cost? Do you expect them to design for the 10,000-year, 100 foot tsunami? Industrial, technological society has only been around for a few hundred years. There are many more ecological, sociological, or financial Dark Swan events inevitably waiting in the wings (see http://twitter.com/#!/DarkSwan2012 for discussion).
Overall, the Japanese nuclear plants did not fare that badly considering the magnitude of the event – no one killed, and only a couple injured from radiation effects. What was the death toll from failing dams, oil and gas refineries and pipelines, underdesigned seawalls, office buildings and residences? Is everything going to have to be designed to withstand the 1000-year earthquake/tsunami? That’s fine until the 10,000 or even 2,000-year event comes along.
If the NRC plans on requiring backfits or hardening for the facilities they regulate to meet the challenges of rare but consequential events, then authorities in charge of other potentially dangerous infrastructure should do the same. The costs will be enormous.
And we haven’t even discussed large meteorite impacts, or solar Coronal Mass Ejections (CMEs), which could take out huge swaths of the worlds electrical grids for months at a time.
The universe, even the planet we evolved on and cherish, is a dangerous place for frail humans. Everyone should have a Plan B (and C and D).
How can anyone take Jaczko serously when he's been found by the Inspector General to have concealed information from the full NRC board in order to influence the decision on Yucca Mountain? He has no qualifications for the job. This guy has been an anti-nuclear activist even before his appointment (by Obama of course) to NRC chairman.
Reply | Report Abuse | Link to thisGood points. Fukushima is an economic disaster, not really an environmental disaster. It will render a small area unuseable for a time, but the larger environmental impact is fairly minor. In order to prevent these far out events from ever causing a problem, we would need to create a government mandatated economic disaster - kind of like they are doing in Germany. Probably better to accept the tiny risk.
Reply | Report Abuse | Link to thisTo all the people who think the only things holding back the nuclear power renaissance in this country are environmentalists and regulations, this article makes it clear that this is not the case. The impacts of a full-scale nuclear accident are beyond devastating; they're unthinkable. If the U.S. government is going to shoulder the liability of a nuclear nightmare (since the private insurance market will NEVER take that risk), they had better make sure that a meltdown is not even a remote possibility. Since $100 Billion is probably a low-ball estimate for the level of damages a meltdown would cause, I consider these safety reviews as a prudent safeguard of the taxpayer's money.
Reply | Report Abuse | Link to thisThe problems is, the reactors we have operating currently are STILL not safe and secure enough as this article made clear. These reactors were generally WAY over budget and chronically behind schedule during their construction. To provide the level of safety and security that prudence requires in light of the Fukushima Disaster, new reactors will have to be built with even MORE expensive safeguards and redundant systems. This will cause even MORE cost and schedule overruns. It's no mystery that utilities are cancelling their reactor construction plans all over the developed world because of these financial and technical nightmares. Gen III+ reactors are still vulnerable and many of these designs provide only a modest reduction in meltdown risk. Aside from cost and safety issues, nuclear power as it stands today still has a waste / nuclear weapons proliferation problem that is inseparable from its fuel cycle.
Energy efficiency, conservation, demand management and renewable energy can scale much quicker and cheaper than nuclear power can.
Uranium based facilities are always going to be dirtier and dangerous. It is time to start looking at a new generation of reactors based on the Thorium fuel cycle.
Reply | Report Abuse | Link to thisThese aging reactors could be replaced by a more economical, safer and efficient technology that can not be used for nuclear proliferation. The question has to be asked: what are we waiting for?
With Thorium? Someone dumb enough to think that thorium fluoride molten salt is anything but utterly insane?
Reply | Report Abuse | Link to thisGuys, forget it. At $4 billion a pop nuclear power is already more expensive than solar thermal, which ain't saying much. Now, consider those costs will at least halve and probably drop by 400% in the next 5 years. It is clear why no SANE BUSINESS PERSON wants to invest in more nuclear reactors. Give it 5 years, the whole industry will be done, stick a fork in it.
This just in: U.S. Nuclear Regulations Inadequate to Cope with Explosion of Sun. Sheesh.
Reply | Report Abuse | Link to thisI appreciate your response, Dark. Fukushima was not the disaster. Japan's biggest earthquake and 45 ft tsunami were the disasters. People could have avoided all casualties by not living in Japan. Or by not doing anything. But then you die of atrophy. Man, this world is dangerous and confusing. Thank you, Sci Am, for helping me to understand the risks i face in my life. I think I will wear a helmet and knee pads everywhere I go now. And a face mask. Maybe I'll just stay inside.
Here are the deaths per TWh for various energy sources:
Reply | Report Abuse | Link to thishttp://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html
Energy Source Death Rate (deaths per TWh)
Coal – world average 161 (26% of world energy, 50% of electricity)
Coal – China 278
Coal – USA 15
Oil 36 (36% of world energy)
Natural Gas 4 (21% of world energy)
Biofuel/Biomass 12
Peat 12
Solar (rooftop) 0.44 (less than 0.1% of world energy)
Wind 0.15 (less than 1% of world energy)
Hydro 0.10 (europe death rate, 2.2% of world energy)
Hydro - world including Banqiao) 1.4 (about 2500 TWh/yr and 171,000 Banqiao dead)
Nuclear 0.04 (5.9% of world energy)
Man, Solar and wind are more dangerous, per TWh, than nuclear. I am wondering if US regulations are inadequate to deal with wind/solar incidents. But maybe we could strap a few more regs on nuclear and reduce that 0.04 deaths per TWh to 0.039 for just a few billion bucks. Of course, that would probably push us into more coal usage, and, at a higher death rate by 4200 to 1, even a one percent increase in coal usage (for a one percent decrease in nuclear) over coal would result in lives saved from a 1% decrease in nuke of 1320 and lives lost from increase in coal of 212,520 for a net loss of life of 211,200 per year. Hmm.
I think otherwise. In the case of nuclear power the whole problem seems to be one of the cooling system not working properly or at all in the case of a nuclear reactor problem.
Reply | Report Abuse | Link to thisIn the case of Chernobyl it was human error durimg a test. Human error and system component break down was involved in Three Mile Island. In the case of Fukushima it was an earthquake followed by a tsunami which destroyed the diesel generator based backup system. Human error was next.
The control of nuclear reactors should not be left to human beings but to highly redundant computer based systems.
Ultimately there will be a failure of all preconceived systems. A proper independant error detection, correction and recovery system should be in place. No such thing exists at the present time.
Mobile error detection, correction and recovery systems should be built for all large scale energy engeneering projects whether they be nuclear, hydro, petroleum, coal or gas based. Nothing should be left to human judgement at the time of error.
This is a gigantic project of enormous cost. However the cost distributed over the many exajoules of energy produced would not amount to anything measurable per kilowatthour.
Reply | Report Abuse | Link to this"U.S. Nuclear Regulations Inadequate to Cope with Incident Like Fukushima"
-Is that a joke? Can anyone here really think of any single structure ever created by man that would survive a tsunami of that magnitude? No, everything was wiped out where the wave hit. Its like saying "We have to come up with stricter regulations to protect our farms from mass extinction events and nuclear bombs".
Look, the Fukushima disaster is a seriously tiny and insignificant disaster in comparison to the Tsunami disaster. From an engineering standpoint, you cannot ask for a better design; design a system so that when failure occurs the cause of the failure is far more devastating than the failure itself. You cannot ask for better engineering.
Imagine, Imagine if an oil refinery were sitting at the fukushima site. If that had occurred, your tsunami would have been on fire, far more toxic and far more deadly and prolonged than it was. So, do you really think everyone would be looking at the refinery regulations? The answer: hell no. One refinery actually blue up in japan, they actually showed the pictures of the exploding refinery on the news while giving the report on fukushima to give their exploitable audience the impression the pictures where from the nuclear site.
There is a blatant agenda to hold up technological progression in the US, and for nothing more than immediate profit, a few cents on every dollar, no long term consideration need be given from oils view point.
And yet ironically you cite Banqiao. A perfect example of the flawed concept of planning for 'once in 1000 (or whatever number) year' events. No sooner did they do that, then a 2000 year event promptly dropped its ugly head on them. The truth is nobody knows how often any given facility is going to be subjected to SOME SORT of unusual and dangerous conditions. Banqiao is also a beautiful illustration of other issues. Had the guy who was supposed to be in charge been listened to and extra sluiceways built then the dam might have held, but no, they wanted to save money. And then beyond that there's NEVER enough money really spent on maintenance and disaster planning.
Reply | Report Abuse | Link to this@jsobry, really? You might want to add up the numbers in a more fiscally realistic way. The cost of dealing with the eventual $1 or 2 HUNDRED BILLION consequences of these disasters is actually pretty high. It is a loss of capital and thus a capital expense and needs to be cost accounted in the same way as the construction cost of a nuclear plant (or any other infrastructure) is. When you do that you find the cost is appreciable. Maybe not ridiculous, but high and definitely has an adverse impact on the cost comparison between nuclear and other sources of power.
Nevertheless we certainly should balance the various cost and risk factors. The problem is actually understanding them and holding people to planning responsibly, both of which are HARD problems.
"The impacts of a full-scale nuclear accident are beyond devastating; they're unthinkable."
Reply | Report Abuse | Link to this-that is blatant lieing. Really, which was beyond devastating, which is unthinkable? 3 mile island? less than 1/10 the amount of radiation in an xray was released. Chernobyl? The only measured effects were a .01% increase in thyroid cancer, far less than the 10% rise in all types of cancer over the last 50 years as the result of air pollution. Fukushima? Where are the dead, and you can't count the tsunami victims? You have been watching way to much propaganda, you probably think a nuclear power plant has the capability to explode like a nuclear bomb and that the cooling towers are smoke stacks, lol. Sorry, but those type of people are the only ones I've ever seen speak like you.
"At $4 billion a pop nuclear power is already more expensive than solar thermal, which ain't saying much."
-solar thermal, I agree with that on a per kilowatt hour basis and assuming the solar thermal site will be maintained for 100+ years.... according to my math. Just so you know, a nuclear site is LITERALLY 1000 times more profitable and infinitely less polluting than a coal site. I'm not saying nuclear is perfect, but compared to coal, it is far beyond perfect... practically godly.
I mean seriously people, there are close to 100,000 people dead as the result of the tsunami and all you seem to care about are 3 or 4 people with minor radiation poisoning.
Let me also say this: There will never be a nuclear disaster greater than that that occured at fukushimi..that was a complete failure and complete meltdown at multiple reactors...so stop the false fear already.
Mmmk. Banqiao wasn't even part of the argument here. I don't understand the irony. It would be ironic if I mentioned how dangerous hydro is (I didn't) then compared that to how safe nuclear is, at which time we find that Banqiao greatly skews the dangers associated with hydro, and that, perhaps, hydro were actually the safer of the two, despite isolated problems at Banqiao.
Reply | Report Abuse | Link to thisAs a matter of fact, even with what may be considered flaws in nuke regulation, it is still the safest form of energy. Now that is a touch of irony. Dispute that fact, and then we can talk.
Now if you simply don't like nuclear (maybe it scares you), just let it be known. But I am curious as to the cause of the phobia as the numbers don't support a rational fear. Further, I am not suggesting that nuke plants can't do a better job, only that it appears unnecessary to blast them while giving a pass to all other forms of energy/industry in general. Further, I don't believe it necessary for the govt to intervene here.
As a geologist I'm amused by those who point to the Japanese crisis as 'proof' of how these plants at the end of the day stood up to a 'major' earthquake and tsunami.
Reply | Report Abuse | Link to thisFolks, what happened in Japan is a pop gun next to a cannon in size in the the potential of what Nature can throw at us. It's playing Russian roulette to build nuclear plants in most of their present locations.
Bottom line...I wouldn't raise my kids within a hundred miles of one. Yes, they can be made safer and nuclear power is going to be make sense but not today with our level of technology.
I find it difficult to understand that either in the initial design of Fukishima layout, or timely modifications as new facts emerged, were not implemented for the tsunami. My understanding is that tsunami wave events of this or greater magnitude are not that infrequent, especially considered in the time frame of a facility that is going to operate for 50 plus years. At least that is what I have read about geological high water marks detected in British Columbia that were presumably caused by tsunamis.
Reply | Report Abuse | Link to thisCosts may have been or would be uneconomical to build the whole facility above worse case scenario, but surely building the emergency diesel gensets way above worst case, or on a moored lighter than water barge that could have rode out the event would not have been a prohibitive outlay. If the gensets had survived, then they would have had power for the pumps and hence water for cooling.
Turning to the hydrogen venting, can somebody explain to me why the vent stacks did not have a normally closed solenoid valve that would have opened automatically when it lost power? Combined with any type of primitive, robust automatic flaring system schemes such as have been used for many decades in the oil and gas industry? So that the gas could have been vented and control burned instead of building up and causing explosions?
If economic solutions for above scenarios are readily available from Marine Engineering 101 and Combustion Engineering 101, I suspect '101' solutions are available from related disciplines for many other historic or foreseeable awkward variables.
The mishap with HTRE 3 (for the Aircraft Nuclear Propulsion (ANP) Program) is one of the main reasons that fully automatic computer control of nuclear reactors is not used. Computer controls are not an adequate substitute for properly trained and supervised operators.
Reply | Report Abuse | Link to thisThe death of 24,000 people from natural causes is no big deal apparently ,and the pollution caused by the fires at the oil refinery and the big storage depot is not even mentioned by those concerned with those above wanting to save the planet.
Reply | Report Abuse | Link to thisThe IAEA report that no one has received a dose of radiation in excess of that allowed by the regulations.
(Go check -their interim report is now available)
This does not prevent hysteria on a site with the word "Scientific" in it.
Does anyone want coal mining banned,because about 2400 Chinese miners were killed in mining disasters last year?
From: "OUR NUCLEAR FUTURE: THE PATH OF SELECTIVE IGNORANCE" by Alex Gabbard, Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN
Reply | Report Abuse | Link to this"For example, using 1991 production figures cited above and assuming that all the coal mined that year was burned somewhere, IAEA average concentration data indicates that at least 10,600 tons of uranium, 23,400 tons of thorium, and 275 tons of K-40 were released into the global biosphere that year alone."
[COAL burning put 10,600 tons of uranium, 23,400 tons of thorium, and 275 tons of K-40 into the environment in 1991.]
"Elemental analysis of coal from around the world reveals that it can be composed of as many as 73 elements"
That is what coal is allowed to do every year because coal contains uranium, thorium and potassium. A nuclear power plant can't do that. In fact, all nuclear power plants all together can't do that.
Coal contains: URANIUM, ARSENIC, LEAD, MERCURY, Antimony, Cobalt, Nickel, Copper, Selenium, Barium, Fluorine, Silver, Beryllium, Iron, Sulfur, Boron, Titanium, Cadmium, Magnesium, Thorium, Calcium, Manganese, Vanadium, Chlorine, Aluminum, Chromium, Molybdenum and Zinc. There is so much of these elements in coal that cinders and coal smoke are actually valuable ores. We should be able to get all the uranium and thorium we need to fuel nuclear power plants for centuries by using cinders and smoke as ore. Unburned Coal also contains BENZENE, THE CANCER CAUSER. We could get all of our uranium and thorium from coal ashes and cinders. The carbon content of coal ranges from 96% down to 25%, the remainder being rock of various kinds.
Chinese industrial grade coal is sometimes stolen by peasants for cooking. The result is that the whole family dies of arsenic poisoning in days, not years because Chinese industrial grade coal contains large amounts of arsenic.
Look up "natural background radiation." All rocks are radioactive, and so are bananas. If you live in Chernobyl the total radiation dose you get each year is 390 millirem. That's natural plus residual from the accident and fire. In Denver, Colorado, the natural dose is over 1000 millirem/year. Denver gets more than 2.56 times as much radiation as Chernobyl! But Denver has a low cancer rate.
Calculate your annual radiation dose:
http://www.ans.org/pi/resources/dosechart/
you are going to have to justify your comment that 'thorium fluoride molten salt is anything but utterly insane'
Reply | Report Abuse | Link to thisthe MSRE proved the viability of the concept back in the 1960's, and it is glaringly obvous that the fast breeders were pursued because the MSR was in fact *too* good - they simply did not want a reactor that produced no usuable weapons-grade material back then. I can back up this statement - can you do the same for yours?
what mishap with HTRE 3? from the information I have, it never progressed past the fabrication of some parts before the project was cancelled.
Reply | Report Abuse | Link to this